I've seen it work and fail on TV, the times it has worked it is allmost alway's after normal grunting.

So to answer the question even though I'm full of horse crap. It may be effective for a very short peroid of time,in area's with a good buck to doe ratio, is it worth the investment hey who knows it could bring you in the buck of a life time,or it could be a waste of money.

The big question is, Is there a scent lok insert for it so the deer don't smell your breath if they come in down wind?